The invention relates to a flexible thermoplastic rack bar for meshing with a gear wheel, particularly intended for the drive of displaceable motor vehicle elements, like roof parts, sliding windows, and the like, having a series of supported teeth and a pull-resistant reinforcement embedded substantially parallel to a separation line of the rack bar.
It is a known rack bar of this kind (German Patent 31 23 554), the rack bar teeth are supported in their root area on one side. As a reinforcement, a steel band is located below the teeth, which has lateral clips which extend into the individual teeth of the rack bar. The manufacture of such a reinforcement is relatively costly, and furthermore, the obtainable tooth height for a preselected height dimension of the rack bar is limited, which has a detrimental effect on the transfer of force, in spite of the clips reaching into the individual teeth.
Similar problems regarding the ratio of cross-sectional surface and transferable force are encountered in connection with another known rack bar (German Gebranchsmuster 85 31 110), in which a series of individual, short rack bar segments made of synthetic material have two wire ropes embedded in the root area of the rack bar teeth, the wire ropes extending parallel to the longitudinal direction of the rack bar, interconnecting the individual segments.